Valentinian I

Valentinian I (321-17 November 375) was Roman emperor from 364 to 375, succeeding Jovian and preceding Valens.

Biography
Valentinian was born in 321, the son of Illyrian soldier Gratian the Elder and the brother of Valens. He served as a tribune under the Roman caesar Julian the Apostate during his campaigns in Gaul against the Alemanni, and he became tribune of an elite infantry regiment under Jovian. In 364, he was acclaimed emperor after Jovian died of illness while leading the army on a retreat from Mesopotamia, and Valentinian made his brother Valens co-emperor. Valentinian ruled Italia, Gaul, Roman Africa, and Illyricum, effectively forming the Western Roman Empire as Valens ruled the Eastern Roman Empire. Valentinian fought against rebels and invading barbarian tribes, and he had a challenging rule as emperor; he died while yelling at Quadi envoys in a fit of rage surrounding their blaming of the Roman-Quadi conflict on Rome.